their extremities the anthers, which, as in all the Composite, are conjoined into a complete tube. At the time of flowering this anther tube is closed at the end, and envelopes the pistil which arises at the base of the corolla from the inferior Ovary. At this period the anther tube rises about four m. m. above the summit of the corolla. When touched pollen masses are extracted from its apex, and at the same time the tube exhibits a peculiar twisting movement. After about five minutes the experiment can be repeated; the pollen is again forced out of the tube, and the twisting movement will be again witnessed." When the filaments are extended they appear as if longitudinally striated; when contracted, as if transversely striated. He considers the fibres to correspond in their behaviour essentially with unstriped muscle; but he regards their shortening as of a passive nature, and due to elasticity, and their lengthening an active condition which is the opposite to what takes place in muscular fibre. He considers that we may now be said to be acquainted with plants which, so to speak, have muscles; and in the lowest animals which possess no muscles their contractile parenchyma behaves after the manner of contractile vegetable cells.

RESPIRATION OF RUMINANTS.-In a paper which will be found in Comptes Rendus M. M. J. Reiset shows that a proto-carburet of hydrogen is emitted during their respiration. He regards it as arising from the changes which their food experiences during digestion. They likewise emit a small proportion of nitrogen. He shows that the consumption of oxygen and emission of carbonic acid gas goes on so quickly that cattle stables require much more ventilation than is generally allowed on old French farms-a remark equally applicable to many in this country.

FUNCTIONS OF THE EAR.-Professor Helmholz, author of an elaborate work entitled Die Lehre von den Tonempfindungen, regards the snail shell or cochlea, as the special organ for transmitting musical sounds to the nerves, while noises affect other portions of the ear. The so-called "fibres of Corti," of which there are about 3000, he considers each capable of being affected by a simple sound, while a compound sound acts upon several, and produces a corresponding impression on the nerves. Each filament of the acoustic nerve is united to an elastic filament, which he supposes to be thrown into vibration by appropriate sounds.

MUSCLES OF THE HEART.-The Archives des Sciences, No. 67, contains a brief account of Dr. Gartaldi's researches on this subject, and which are published in the Wurzburger Naturwissenchaftliche Zeitschrift. It appears that Weissman established a great difference between the muscles of the heart and other striated muscles. He demonstrated that the hearts of the invertebrata, of fishes, and of batrachians are composed of cells during their whole existence; while in reptiles, birds, and mammals, including man, the cells only exist during the embryonic period, and at a later stage are transformed into muscular fibres. Weissman thought this change took place by fusion of many cells, a theory not according with observations of Remak, Lebert, and Kölliker. Gartaldi's observations on the hearts of pigeons show that the muscular fibres do not result from the fusion of cells, but that they must be considered as primitive fascia. With respect to the nucleus he has always seen it in the axis of the fibre in the birds and mammals which he has examined, a character which is only found in the embryonic fibre of voluntary muscles, and he therefore concludes that the muscular structure of the heart in the vertebrata presents a phase of development inferior to that of the fibres of the muscles of voluntary motion.

BABINET ON THE LUNAR ECLIPSE, JUNE 1.-M. Babinet states in Cosmos that this eclipse presented a peculiarity not before noticed. When the moon left the earth's shadow and formed a crescent, whose greatest breadth was equal to one quarter of the moon's semi-diameter, the eastern half was illuminated while the western half remained in shade. This appearance lasted so long as to leave no doubt that at the end of the eclipse the shadow of the earth extended further on the western than on the eastern side of the meridian of Paris. M. Babinet explains the reason of this phenomenon as follows:-He states that at a pressure of seventy-six centimeters, the refraction of the atmosphere amounts to thirtyfive minutes with regard to rays that reach us from the horizon, and seventy minutes for those solar rays which pass close to the earth's surface, and traverse

the atmosphere again before escaping behind the earth, and that thus the illumination of the atmosphere diminishes the earth's shadow by more than twice the diameter of the moon. The bent rays are the first to reach the moon as she emerges from the shadow. As the refraction is proportioned to the density of the air, those rays which traverse the atmosphere at a considerable elevation are less bent than those which pass close to the earth. On the 1st of June the solar rays passed over the earth's surface in the middle of Greenland. In the western part of the circle of illumination the rays traversed the air above glaciers which have an elevation of at least 500 meters, while at the eastern part they traversed the air close to the open sea, and having a refractive power of seventy minutes, that of the air above the glaciers being refracted at least four minutes less. This accounts for light reaching one part of the lunar crescent before the other.

AN INNOCENT GREEN.-Cosmos gives the following as the composition of an innocent green for house painting and paper hanging, and which ought to replace the poisonous arsenical greens. It is called "English green," and contains

Sulphate of baryta
Protoxide of iron
Silica

Alumina

Soda

0.780
0.040;

0.088

0.040

0.025

0.007

0.020

1.000

Lime

Water and loss

NEW PROCESS OF ENGRAVING.-Cosmos gives the following as the process of M. Dulos:-A plate of copper is covered with a varnish of india-rubber and zine white. Lines are traced through this surface down to the metal by an ivory point. The plate is then plunged in a solution of hydrochlorate of ammonia, the positive electrode being a plate of iron in communication with the negative pole of the pile. Iron is deposited on all the parts of the copper exposed by the ivory point, but not on the varnish, which is removed by benzine. The plate is once more exposed to electric action in a bath of silver, and that metal is precipitated on the copper but not on the iron. It is then heated to 80° C., and an alloy fusible at that temperature is poured over it. The liquid moistens the silver and adheres to it, but not to the iron, which it does not moisten. When cold the fusible alloy will be found standing on each side of every line, and forming a mould, from which a new plate, adapted to printing, is obtained by a galvanoplastic process.

REPRODUCTION OF LITHOGRAPHS.-The following note from M. Rigaud has been presented to the French Academy :-"I apply the back of a lithograph to a layer of pure water for a few minutes; it moistens uniformly, and the water does not wet the black portions. I withdraw it and place it between two folds of paper to remove excess of moisture, and then stretch it face downwards upon a lithographic stone, to which it adheres by slight pressure. I then take a sheet of ordinary paper and moisten it with the nitric acid of commerce diluted with ten times its bulk of water. Removing the superfluous acid by two folds of paper as before, I press this acidulated sheet upon the lithograph. The nitric acid works its way slowly through the moistened lithograph, and acts uniformly on the stone with disengagement of carbonic acid gas, which penetrates the pores of the paper as fast as it is produced."

LIONEL BEALE ON NERVE CELLS.-Mr. Beale's researches lead to the conclusion, "1. That in all cases nerve fibres are in bodily connection with the cell or cells which influence them, and this from the earliest period of their formation. 2. That there are no apolar cells, and no unipolar cells in any part of any nervous system. 3. That every nerve cell, central or peripheral, has at least two fibres connected with it.”—Proceedings of the Royal Society, No. 56.